1. Field of the Invention
This invention relates generally to vehicle passenger safety restraints and, more specifically, to an Improved Bus Seat Safety Restraint.
2. Description of Related Art
Mass transportation vehicles such as buses have been widely used in virtually every city and town in the developed world for decades. Generally speaking, these vehicles typically include two or more columns of bench seats aligned one behind the other with a minimum necessary distance between a seat and the seat behind it. It is uncommon to find automobile-type lap or shoulder restraints for the passengers on public transportation vehicles, apparently because passengers repeatedly fail to engage the belts, either due to carelessness or due to perceived discomfort. In general, then, there is not currently a widely used restraint system to prevent passengers of mass transportation systems from being tossed from their seats in the event of a vehicle collision or rollover.
This problem is particular egregious in the case of school buses. Many children ride the bus to and from school five days a week in all weather, traffic and road conditions. The high frequency of ridership under a variety of conditions indicates that it is inevitable that more children passengers will experience a collision while riding a bus than virtually any other passenger group. This is exacerbated by the fact that children can tend to be particularly unruly while riding the bus to and from school; the children cannot be relied upon to engage the current safety restraints, even if they were provided. What is needed, therefore, is a safety restraint system for vehicles with bench seats that is easy to use and to be monitored.
Majerus, U.S. Pat. No. 4,681,344 sought to solve this problem. The Majerus unit comprises a hinged, U-shaped bar attachable to the legs of each forward seat in a column and a releasable belt which holds the bar in a lowered position, laying across the passengers' laps, restraining them from striking the seat in front of them. When not in use, the Majerus belt is released, and the bar is pivoted up to the stowed position. There are three serious problems with the Majerus system: (1) the locking belt system is as difficult to enforce as a common lap belt--if the passenger pulls down the bar (i.e. to mislead the driver into believing that the bar is engaged), but fails to lock the belt, the system will not provide any restraint; (2) the Majerus belt extends from the bar to the seat at the aisle side of the seat, thereby trapping the restrained passengers in the seat until the belt is released; and (3) the system relies upon the passenger to adjust the belt until the bar is in the proper position--if the belt is left too loose, the bar won't provide restraint to the passengers, and may even be a hazard. What is needed, therefore, is a bus passenger safety restraint that is easily engaged, automatically adjusted, and easily verified as such by the bus driver. This system should further permit the passengers to easily egress in case of system malfunction.
Amabile, U.S. Pat. No. 4,796,913 sought to solve some of the Majerus problems. The Amabile device is also a hinged U-shaped bar attached to the next seat forward. The Amabile device differs from Majerus in that it attaches to the seatback frame directly and does not require a belt for engagement. The Amabile system comprises a pair of pivoting cam hinges at each end of the U-shaped bar attached to either side of the forward seatback frame. These cam hinges define three bar positions: an upper limit (stowed position), a lower limit, and a lower locked limit. The Amabile bar is automatically engaged in the lower locked limit position whenever the restrained passengers' inertia forces the bar forward and into the lower locked cam in the hinges.
One serious problem with the Amabile system is that it is only responsive to a passenger accelerating forward relative to the seats, such as in a front-end collision. The Amabile bar will not restrain the passengers in the event of a side collision, or in a bus rollover. Furthermore, the Amabile bar is not height-adjustable by the passengers for their particular thigh height. Once installed, the Amabile cam hinge has a set locked position that cannot be adjusted; it is conceivable that a passenger with sufficiently large thighs will prevent the bar from dropping down low enough to engage if a collision occurs. Finally, the Amabile bar is difficult to install in existing buses. In order to activate both cam hinges (i.e. on both ends of the bar), the cams must be aligned with each other to a very close tolerance. Misalignments due to seat frame bending or simply inconsistent installations may create a situation where one hinge's cam locks while the other hinge doesn't. What is needed, therefore, is a safety restraint system that engages and locks in front, and side collisions, and even in the event of vehicle rollover. The system should be easily installed and aligned on existing buses, and further should provide adjustability for differing passenger body types.